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  <title>Gamma-corrects an image</title>

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</div><hr /><div id="imagick.gammaimage" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">Imagick::gammaImage</h1>
  <p class="verinfo">(PECL imagick 2.0.0)</p><p class="refpurpose"><span class="refname">Imagick::gammaImage</span> &mdash; <span class="dc-title">Gamma-corrects an image</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-imagick.gammaimage-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="type">bool</span> <span class="methodname"><strong>Imagick::gammaImage</strong></span>
    ( <span class="methodparam"><span class="type">float</span> <code class="parameter">$gamma</code></span>
   [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$channel</code><span class="initializer"> = Imagick::CHANNEL_ALL</span></span>
  ] )</div>

  <p class="para rdfs-comment">
   Gamma-corrects an image.  The same image viewed on different devices will
   have perceptual differences in the way the image&#039;s intensities are
   represented on the screen.  Specify individual gamma levels for the red,
   green, and blue channels, or adjust all three with the gamma parameter.
   Values typically range from 0.8 to 2.3.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-imagick.gammaimage-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">gamma</code></em></dt>

     <dd>

      <p class="para">
      The amount of gamma-correction.
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">channel</code></em></dt>

     <dd>

      <p class="para">
       Provide any channel constant that is valid for your channel mode. To
       apply to more than one channel, combine channeltype constants using
       bitwise operators. Refer to this
       list of  <a href="imagick.constants.html#imagick.constants.channel" class="link">channel constants</a>.
      </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-imagick.gammaimage-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>TRUE</code></strong>。
  </p>
 </div>


 <div class="refsect1 errors" id="refsect1-imagick.gammaimage-errors">
  <h3 class="title">错误／异常</h3>
  <p class="para">
   错误时抛出 ImagickException。
  </p>
 </div>


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